In the study, a secondary analysis of data from a randomized, controlled trial of the effects of azithromycin on the frequency of AECOPD, no relationship was found between baseline Vitamin D levels and time to first AECOPD or between vitamin D levels and AECOPD exacerbation rates.
"Vitamin D insufficiency and deficiency are common in patients with COPD, and patients with severe COPD are at the highest risk for exacerbations, so we hypothesized that low vitamin D levels might increase the risk of AECOPDs," said Ken M. Kunisaki, M.D., of the Minneapolis Veterans Affairs Medical Center. "Our negative results are in contrast with earlier studies in which lower vitamin D levels were associated withhigher rates of respiratory infections in adults and more frequent asthma exacerbations in children."In the current study, mean forced expiratory volume in one second (FEV1) was 1.12L, 40% of predicted. Mean vitamin D level at baseline was 25.7 ¡À 12.8 ng/mL, with 33.1% of subjects categorized as vitamin D insufficient (¡Ý20 ng/mLbut
During 1 year of follow-up, study subjects experienced a total of 1415 AECOPDs. Of 973 patients,360 (37%)remained AECOPD-free, 278 (29%) had 1 AECOPD, 133 (14%)had 2 AECOPDs, and 202 (21%) had 3 or moreAECOPDs.
In the primary analysis, vitamin D levels had no relationship to time to first AECOPD; for a 10 ng/mL increment in vitamin D level, the estimated hazard ratio was 1.04 (95% confidence interval: 0.97-1.12). In secondary analyses, vitamin D levels were not related to annualized rates of AECOPDs in either Poisson (p=0.82)or negative binomial analyses (p=0.87).
Patients with severe vitamin D deficiency had a higher mean rateof AECOPDs, but this difference was not statistically significant. Patients with severe vitamin D deficiency did not exhibit faster time to first AECOPD than other patients.
The study had some limitations. Vitamin D levels were only assessed at baseline, and so may have changed during the study period. Seasonal changes in vitamin D levels may also have occurred.
"Contrary to what we expected, baseline vitamin D levelswere not related to the risk of subsequent AECOPDs in this large group of COPD patients at high risk of AECOPD," Dr. Kunisaki said. "Vitamin D supplementation is unlikely to have an effect on AECOPD risk in these patients."
About the American Journal of Respiratory Research and Critical Care Medicine:
With an impact factor of 10.191, the AJRRCM is a peer-reviewed journal published by the American Thoracic Society. It aims to publish the most innovative science and the highest quality reviews, practice guidelines and statements in the pulmonary, critical care and sleep-related fields. Founded in 1905, the American Thoracic Society is the world's leading medical association dedicated to advancing pulmonary, critical care and sleep medicine. The Society's 15,000 members prevent and fight respiratory disease around the globe through research, education, patient care and advocacy.
Nathanial Dunford | EurekAlert!
'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers
16.02.2018 | National University of Science and Technology MISIS
New process allows tailor-made malaria research
16.02.2018 | Eberhard Karls Universität Tübingen
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
20.02.2018 | Life Sciences
20.02.2018 | Medical Engineering
20.02.2018 | Physics and Astronomy